1. Field of the Invention
The invention relates to pavement cutting equipment, and more particularly, to relatively small, portable pavement cutting devices which can be removably attached to a blade of an earth moving machine.
2. Description of the Prior Art
There are numerous occasions on which it is desirable to have available an inexpensive, portable pavement cutting device. For example, employees of public utilities, road construction workers, and general contractors, frequently need to cut through asphalt pavement for various reasons. Frequently, workers utilize ordinary hand-held "jack-hammers" having pointed cutting tips. This procedure for cutting pavement is unduly slow, and laborious, especially when the pavement is cold (since asphalt pavement become excessively hard and brittle when it is very cold). A number of pavement cutting devices are known. Some of the known pavement cutting devices utilize rotary cutting wheels which function as high speed rotary saw blades, cutting through the pavement. A device of this type is disclosed in U.S. Pat. No. 2,701,134. The machine disclosed in this reference is unduly expensive, and could not be conveniently used for each of the many pavement cutting tasks frequently required of a contractor or public utility. Furthermore, sawing operations on asphalt pavement result in excessive wear on saw blades, and the cutting achieved is unduly slow. Other types of pavement cutting wheel attachments having circular cutting discs with smooth peripheral cutting edges have been proposed, such as those disclosed in U.S. Pat. Nos. 3,472,554, 3,743,358, and 3,515,435. Another device having a smooth, continuous cutting edge is disclosed in U.S. Pat. No. 3,355,214 and yet another is disclosed in U.S. Pat. No. 4,076,314. While the devices disclosed in the immediately foregoing patents are capable of satisfactorily cutting through warm asphalt pavement at a satisfactorily high rate, they are incapable of doing so if the asphalt is cold. U.S. Pat. No. 3,271,079 discloses a complex pavement cutting machine which includes a smooth blade cutting disc and a large, bulky mechanism powered by a gasoline engine for imparting a high frequency up-and-down and forward-and-backward vibratory motion to an arm supporting the cutting wheel. However, the small (1/8 inch) displacement of the vibratory motion, while tending to slightly improve the cutting action of the cutting wheel, is totally inadequate to enable the cutting wheel to efficiently penetrate and divide cold asphalt pavement. There is clearly an unmet need for a small, portable, inexpensive, efficient pavement cutting machine capable of efficiently cutting through cold asphalt pavement.
Accordingly, it is an object of the invention to provide a low cost, portable pavement cutting device which is removably attachable to a cutting blade of an earth moving machine.
It is another object of the invention to provide a pavement cutting machine wherein a freely rotatable cutting disc is enabled to penetrate cold asphalt in response to a particular average downward force imparted to the cutting wheel more rapidly and more efficiently than any pavement cutting wheel known in the prior art.
Still another object of the present invention is to provide a pavement cutting device which overcomes the above mentioned shortcomings of the prior art.